Method of and means for perforating wire-gauze fabric and the like



l. A. S. BECKER. METHOD OF AND MEANS FOR RERFORATING WIRE GAUZE FABRIC AND THE LIKE APPLIC ATION FILED JULY 10. mm.

1,368,233. "Pamnwa Feb. 15,1921.

02720 67270? 9 ajojhn/ flhfilljeczef' UNITED STATES PATENT OFFICE.

JOHN A. S. BECKER, OF CHICAGO, ILLINOIS, ASSIGNOR TO BECKER CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

BROTHERS, on

METHOD OF AND MEANS FOR PERFORATING WIRE-GAUZE FABRIC AND THE LIKE.

Application filed July 10,

My invention relates to a method of and 7 means for the like. I i i In his pending application, Serial Numperforating wire gauze fabric and her 301,675 filed June 4t, 1919, Oliverl l.

Becker has disclosed a wire gauze brush for electrical machinery, the various layers of which brush are connected by perforating the brush fabric and inserting localized connections or holding rivets therein.

While my invention is particularly useful in connection with the perforation of such materials as the brush fabric employed in connection with the above application, I do not intend to limit the invention to such use or purpose only.

I have found that in perforating bodies of gauze fabric or similar material with the various types of perforating tools or punches now on the marketthat the material adjacent the upper face of the body isshifted downwardly upon movement of the perforating tool therethrough, leaving a depression about the upper edge of the perforation thus provided. The material adjacent the lower face of the body is spread or forced out ofthe plane: of the body leaving a bur or roughness about the lower edge of the opening after the punch or perforating tool has been withdrawn. In the event that the perforated brush body is to be mounted in a guide or terminal piece these irregularities-depressions and burs-upon the oppo- Site faces of the brush body not only prevent proper contact between the brush body and the terminal piece or guide but present an unfinished appearing job. Thus, a considerable practical difliculty is frequently encountered, to effectively overcome which has heretofore been impossible even upon the application of pressure to the brush body upon completion of the perforating operation. I

It is an aim of my invention to provide a Specification of Letters Patent.

Patented Feb. 15, 1921.

1919. Serial No. 309,942.

novel principle of and means for perforating a body of wire gauze fabric or similar material without leaving such irregularities. upon the opposite faces thereof: i

It is a further aim of my invention to provide a novel perforating tool or punch for carry ng out this novel principle of my lnventlon in a simple andinexpensive manner.

In accordance with the teachings of my invention I have provided for perforating abody of gauze fabric or the like and removing such irregularities as are formed upon the opposite faces thereof by a single perforating operation.

In order to explain to those skilled in the art the manner in which the principle of my invention is to be applied and to explain a specific embodiment of the invention, I shall describe in connection with the accompanying drawings the perforation of a body ofwire gauze fabric.

Figures 1, 2 and 3 are fragmentary sectional views showing various stages in the perforation of abody of gauze fabric in accordance with the teachings of my invention; and r Fig. 4t shows an alternative form of perforating tool or punch for carrying out my invention.

Referring first to Fig. 1 of the drawings, the work or body of material 1, to be perforated, is interposed between the usual die 8 and clamping piece 10. The die 3 is provided with the usual aperature 4 for cooperation with the perforating tool or punch The clamping piece 10 which is clamped to the die 3 in any suitable manner as at its oppositeends, in addition to clamping the body of material securely in place serves to strip the fabric from the perforating tool 2 with the withdrawal of the perforating tool subsequent to the perforating ruoeration.v

Thereafter the body of material-wire gauze fabric in this particular instanceis operated upon by the perforating tool or punch 2, which perforating tool or pun h is preferably secured in the end of the usual punch press'plunger as well understood by those skilled in the art. The operating pressure for forcing the punch 2 into cooperation with the aperture 4, provided in the die 3, can be applied in any desired manner.

The body of material 1, is thus perforated gauze downwardly as'the punch 2 descends therethrough, as shown at 5 in Fig. 2. Consequently a considerable depression 12 is formed upon the upper surface of the materialand'a considerable bur or roughness 6 is formed upon the lower surface of the gauze fabric about the opening 7. Heretofore in the art these'irregularities 6 and 12 have been left after the perforating tool or.

punchhas been-withdrawn. The removal of these irregularities has heretofore pre-- sented considerable difficulty, not only requiring another operation, but being frequently impossible to effectively accomplish.

I have provided whereby the gauze fabric 5 forced or shifted downwardly when the perforating tool or punch 2 descends therethrough, is shifted back into the normal plane of the body of fabric 1 upon the withdrawal of the punch, leaving the upper surface of the fabric without irregularities and the lower edge of the opening or perforation 7 without a bur or roughness and as clean cut as the upper'edge thereof, as shown in Fig. 3. This is accomplished in the specific embodiment of my invention disclosed by providing an annular groove 9 in the perforating tool 2 adjacent its lower or perforating end. This annular groove 9 provides an annular shoulder 8 which annular shoulder 8 during the upward movement of the perforating tool 52 engages such gauze fabric as has been forced or shifted downwardly out of the plane of the brush to form the bur 6 and depression 12, shifting this gauze fabric back into the normal plane of the body '1 and leaving the upper and lower faces of the gauze fabric without irregularities. Fig. 8 shows the body of gauze fabric 1 subsequent to the perforating operation, and the withdrawal of the perforating tool 2, all irregularities about the edges of the perforation 7, having been effectively removed. The perforating tool or punch 2 can be provided with a plurality of annular shoulders 8 if so desired, as shown in Fig. 4;.

Obviously the perforating tool 2 need not necessarily be of the particular type disthe specific disclosure or precise utility specified, but aim to cover all modifications and adaptations coming within the scope'of the invention as set out in the appended claims.

I claim: a

The method of perforating a material of substantially stiff characteristic 'and normally tending to form non-pliant depressions and burs around the edges of the perforation, which consists in forcing a punch through the materlal and opening a hole thereln, and then causmg positive engagement between the burred or depressed edges of the material and the sides of the punch to cause said burred or depressed edges to be bent back when the punch is withdrawn.

2. The method of perforating a body of stiff fibrous material of metallic characteristic which consists in forcing a punch having an annular shoulder through the material and opening a hole and then causing engagement between the ends of the fibers and said annular shoulder to cause the fibers to be bent back when the punch is withdrawn.

3. In combination a punch for opening a hole in a stifi fibrous material normally i. tending to form non-pliant depressions and burs around the edges of the hole, a die having an aperture for cooperation with said punch, said punch having means for .positively engaging the ends of the'fibers cent the hole to cause the fibers to be bent back when the punch is withdrawn.

4. A. punch for perforating wire gauze or similar material normally tending to form non-pliant depressions and burs around the edges of the perforations, said punch being formed with an annular shoulder above its cutting edge, said annular shoulder func tioning to positively engage the bent edges of the material around the perforation, and

to bend these edges back into a normal plane when the punch is withdrawn. 1

In witness whereof I hereunto subscribe my name this 27th day of June, 1919.

JOHN A. s. BECKER. 

